How can I reuse or recycle carpet underlay?

Not ones to rush, we’re finally getting some carpet fitted in the room we started renovating when we first bought this house last September.

Now this might be carpet sales person nonsense but all the guides we’ve read about choosing a carpet say that the carpet will last a lot longer and wear better if you replace the underlay at the same time. The underlay in the room in question is a very good make apparently but judging by the carpet, has been there for at least 20 years. The old carpet is clearly worn along certain paths and we’re guessing even though it’s harder to see it, the underlay is similarly worn – so we’ve listened to the advice and are replacing it.

Now of course that means we know have both carpet and carpet underlay to get rid of – doubling the amount of stuff to reuse or recycle.

We’ve already covered old carpet in the past and I will certainly keep some of the carpet for those reuses – insulating the floor of our greenhouse for one, and I think some of the carpet might be suitable for making into doormats etc. But what can I do with the underlay?

This is a lot thicker and floppier than the stuff used under wooden or laminate floors. I’m tempted to say it’s foam rubber but I’m not sure it is, and I can’t find out any more about it online, other than it uses “advanced polymers”.

Any suggestions? And any advice on whether the “you have to get new underlay” thing is true or bunk?

Another idea, it can be cut up in sections and used as mats for
other places in your home?? You said you’re already going to use the carpet in your greenhouse, maybe you can find uses for the underlay out there, for maybe cushioniong certain places in there. Also as Alison Bailey said, wrapping around pipes and using it for other INSULATION purposes.
May insulating places in your green house. It would make a great insulator!

There are carpet pad recyclers, unfortunately they are few and far between. I have heard they will even pay you for your used carpet pad. I couldn’t find one in my area (closest one was 12 hours away). Ask your local carpet stores and recycle centers if they know of one in your area.

i layered 5 or 6 pieces the same size, and made a big pillow case to slide it into, for my best friend. She loves it, i can toss the cover in the wash, and it;’s wonderful to step on a thick squishy padding to soothe those tired feet. “Thumper doesn’t mind”

The ideas about insulation are good ones especially if the underlay is like the stuff in the photo on this page. This kind of underlay has airspaces in it due to the undulating/corrugated rubber underside and as everyone knows, dead air spaces help in insulation.
I’ve also given carpet and underlay away to local charities, looking for things that will help disadvantaged people get started in a new home. Needs to be as clean as possible obviously though.

We have been to a few meetings with carpet recycling UK and the general consensus is that most new underlays (pu) are made out of recycled products and because of the glues that are used, cannot be recycled again.-its mad!
The old wool felts and hair felt underlays (as long as they have no an made fibres) will rot down – there is a scheme running with using wool carpets as a fertilizer, if it can be done with that- they may be able to do it with the woolfelt.

Usually when replacing carpet you no or almost no new underlay. How? Easy, the underlay shows very clearly where the wear has been, so swap the worn bits of underlay with that from low wear areas. Only if the wear is very serious do you need ANY new underlay (or use the old underlay you have in the attic?).